Design of the High Pressure Ratio Transonic 1-1/2 Stage Fan Demonstrator Hulda

2007 ◽  
Author(s):  
Hans Ma˚rtensson ◽  
Jo¨rgen Burman ◽  
Ulf Johansson
Keyword(s):  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Demonstration Program ◽  
Good Efficiency ◽  
High Pressure Ratio ◽  
Mechanical Constraints ◽  
Computational Analyses ◽  
Variable Inlet Guide Vane ◽  
First Time

As the first design in a demonstration program for future fighter engine fans a 400 mm 1-1/2 stage fan has been designed and built. A new method including mechanical constraints for designing the blades and gas path is used for the first time on a new design. The approach closely integrates CFD for performance and FE methods for the structure. By this, advanced computational analyses affect the design from the early stages. A design that is successful in achieving good efficiency based on CFD as well as reasonable aeromechanical properties based on FE is derived. The fan incorporates a front frame (FF), variable inlet guide vane (VIGV), rotor 1 (R1) and stator 1 (S1).

scholarly journals The Mach 2 Axial Flow Compressor Stage

1975 ◽  
Author(s):  
F. A. E. Breugelmans
Keyword(s):  
High Pressure ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Compressor Stage ◽  
High Pressure Ratio ◽  
Flow Compressor ◽  
Original Configuration

A supersonic compressor stage has been designed for a high pressure ratio at a tip relative inlet Mach number of 2. The stage was operated in the original configuration, but serious inlet stall occurred at part-speed operation. An inlet blockage ring, a bleed system and a variable geometry inlet guide vane have been analyzed and applied to this configuration. The results obtained with the bleed system in the complete stage are presented. The rotor performance is discussed and compared with the stage performance.

Unsteady Blade and Disk Resonant Stress Analysis Due to Supersonic Inlet Guide Vane Wakes

2008 ◽  
Author(s):  
G. Nordwall ◽  
M. Leduc ◽  
A. Demeulenaere
Keyword(s):  
Stress Analysis ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Electrical Power ◽  
Specific Power ◽  
Inlet Guide Vane ◽  
Wake Structure ◽  
High Pressure Ratio ◽  
High Order Harmonic ◽  
Final Design

A high specific-power radial inflow turbine is currently being designed for installation in the fall of 2008. This turbine will generate 7,000–18,500 HP (5–14 MW) of electrical power. Operating with a relatively high pressure ratio and high molecular weight (58), which is common in geothermal power generation applications, the process has the ability to produce a very strong wake structure. Such wakes have caused catastrophic impeller fatigue failures in similar applications. To prevent a failure, the current design is based on a study of the interaction between the wake structure and the impeller. The SAFE and Campbell diagram are used for screening purposes, but the final design is analyzed using an unsteady CFD analysis coupled with time-dependent Finite Element Stress analysis. This pairing of CFD and FEA analysis allows the alternating torque to be determined both under resonant and non-resonant conditions. With this analysis, it is possible to approximate the stress resulting from higher order resonant frequencies which cannot be avoided in blade tuning. The analysis has shown that a high order harmonic of the vane passing frequency will not lead to unacceptable alternating stress levels. To facilitate future analysis, the 360° unsteady solution was compared to a harmonic analysis with two harmonic frequencies. The harmonic solution has shown good agreement with the full 360° solution.

The Use of Variable Inlet Guide Vane or Speed Control to Maintain Constant Compressor Pressure Ratio in Wet Gas Flow and Their Effect on Diffuser Stability

2017 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Gas Flow ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Gas Production ◽  
Inlet Guide Vane ◽  
Two Phase ◽  
Inlet Stream ◽  
Wet Gas ◽  
Compressor Pressure Ratio ◽  
Variable Inlet Guide Vane

Improving offshore gas production requires the process compressor to be moved closer to the wellhead. This will yield such benefits as enhanced well output, longer well life and the possibility of exploiting smaller fields. However, the harsh environment, remote location and variable two-phase characteristics of an untreated gas stream pose increased challenges for operational performance and robustness. Several methods are available to ensure that a process compressor maintains constant outlet pressure regardless of inlet stream properties and flow. Two pressure-ratio control methods — variable inlet guide vanes (IGV) and variable speed — have been investigated. Their effect on diffuser stability has been tested and analysed in dry and wet conditions. Increased diffuser stability in wet conditions with IGV has been discussed and results are presented.

scholarly journals Effect of the Reynolds Number and Clearance Flow on the Aerodynamic Characteristics of a New Variable Inlet Guide Vane

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 172
Author(s):  
Hengtao Shi
Keyword(s):  
Reynolds Number ◽  
Guide Vane ◽  
Three Dimensional ◽  
High Growth ◽  
Aerodynamic Characteristics ◽  
Inlet Guide Vane ◽  
Separation Region ◽  
Clearance Flow ◽  
New Type ◽  
Variable Inlet Guide Vane

Recently, a new type of low-loss variable inlet guide vane (VIGV) was proposed for improving a compressor’s performance under off-design conditions. To provide more information for applications, this work investigated the effect of the Reynolds number and clearance flow on the aerodynamic characteristics of this new type of VIGV. The performance and flow field of two representative airfoils with different chord Reynolds numbers were studied with the widely used commercial software ANSYS CFX after validation was completed. Calculations indicate that, with the decrease in the Reynolds number Rec, the airfoil loss coefficient ω and deviation δ first increase slightly and then entered a high growth rate in a low range of Rec. Afterwards, a detailed boundary-layer analysis was conducted to reveal the flow mechanism for the airfoil performance degradation with a low Reynolds number. For the design point, it is the appearance and extension of the separation region on the rear portion; for the maximum incidence point, it is the increase in the length and height of the separation region on the former portion. The three-dimensional VIGV research confirms the Reynolds number effect on airfoils. Furthermore, the clearance leakage flow forms a strong stream-wise vortex by injection into the mainflow, resulting in a high total-pressure loss and under-turning in the endwall region, which shows the potential benefits of seal treatment.

Quick Start of an Industrial Gas Turbine Engine Through the Development of “Silent Start” VGV Schedule

2020 ◽  
Author(s):  
Senthil Krishnababu ◽  
Vili Panov ◽  
Simon Jackson ◽  
Andrew Dawson
Keyword(s):  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Rotor Blades ◽  
Start Time ◽  
Turbine Engine ◽  
High Pressure Ratio ◽  
Compressor Map ◽  
Industrial Gas Turbine

Abstract In this paper, research that was carried out to optimise an initial variable guide vane schedule of a high-pressure ratio, multistage axial compressor is reported. The research was carried out on an extensively instrumented scaled compressor rig. The compressor rig tests carried out employing the initial schedule identified regions in the low speed area of the compressor map that developed rotating stall. Rotating stall regions that caused undesirable non-synchronous vibration of rotor blades were identified. The variable guide vane schedule optimisation carried out balancing the aerodynamic, aero-mechanical and blade dynamic characteristics gave the ‘Silent Start’ variable guide vane schedule, that prevented the development of rotating stall in the start regime and removed the non-synchronous vibration. Aerodynamic performance and aero-mechanical characteristics of the compressor when operated with the initial schedule and the optimised ‘Silent Start’ schedule are compared. The compressor with the ‘Silent Start’ variable guide vane schedule when used on a twin shaft engine reduced the start time to minimum load by a factor of four and significantly improved the operability of the engine compared to when the initial schedule was used.

scholarly journals Gas turbine efficiency and ramp rate improvement through compressed air injection

2020 ◽  
pp. 095765092093208 ◽  
Author(s):  
Kamal Abudu ◽  
Uyioghosa Igie ◽  
Orlando Minervino ◽  
Richard Hamilton
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Injection Rate ◽  
Inlet Guide Vane ◽  
Heavy Duty ◽  
Part Load ◽  
Surge Margin ◽  
Rate Improvement ◽  
Heavy Duty Gas Turbine ◽  
Variable Inlet Guide Vane

With the transition to more use of renewable forms of energy in Europe, grid instability that is linked to the intermittency in power generation is a concern, and thus, the fast response of on-demand power systems like gas turbines has become more important. This study focuses on the injection of compressed air to facilitate the improvement in the ramp-up rate of a heavy-duty gas turbine. The steady-state analysis of compressed airflow injection at part-load and full load indicates power augmentation of up to 25%, without infringing on the surge margin. The surge margin is also seen to be more limiting at part-load with maximum closing of the variable inlet guide vane than at high load with a maximum opening. Nevertheless, the percentage increase in the thermal efficiency of the former is slightly greater for the same amount of airflow injection. Part-load operations above 75% of power show higher thermal efficiencies with airflow injection when compared with other load variation approaches. The quasi-dynamic simulations performed using constant mass flow method show that the heavy-duty gas turbine ramp-up rate can be improved by 10% on average, for every 2% of compressor outlet airflow injected during ramp-up irrespective of the starting load. It also shows that the limitation of the ramp-up rate improvement is dominated by the rear stages and at lower variable inlet guide vane openings. The turbine entry temperature is found to be another restrictive factor at a high injection rate of up to 10%. However, the 2% injection rate is shown to be the safest, also offering considerable performance enhancements. It was also found that the ramp-up rate with air injection from the minimum environmental load to full load amounted to lower total fuel consumption than the design case.

Aerodynamic Investigations of a Variable Inlet Guide Vane With Symmetric Profile

2014 ◽  
Author(s):  
David Händel ◽  
Reinhard Niehuis ◽  
Uwe Rockstroh
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Guide Vane ◽  
Reynolds Numbers ◽  
Boundary Layer Transition ◽  
Inlet Guide Vane ◽  
Experimental Investigations ◽  
Wide Range ◽  
Variable Inlet Guide Vane ◽  
Symmetric Profile

In order to determine the aerodynamic behavior of a Variable Inlet Guide Vane as used in multishaft compressors, extensive experimental investigations with a 2D linear cascade have been conducted. All the experiments were performed at the High-Speed Cascade Wind Tunnel at the Institute of Jet Propulsion. They covered a wide range of Reynolds numbers and stagger angles as they occur in realistic turbomachines. Within this work at first the observed basic flow phenomena (loss development, overturning) will be explained. For the present special case of a symmetric profile and a constant decreasing chord length along the vane height, statements about different spanwise position can be made by investigating different Reynolds numbers. The focus of this paper is on the outflow of the VIGV along the vane height. Results for an open flow separation on the suction side are presented, too. Stall condition can be delayed by boundary layer control. This is done using a wire to trigger an early boundary layer transition. The outcomes of the trip wire measurement are finally discussed. The objective of this work is to evaluate the influence of the stagger angle and Reynolds number on the total pressure losses and the deviation angle. The results of the work presented here, gives a better insight of the efficient use of a VIGV.

Forward Swept Rotor Studies in Multistage Fans With Inlet Distortion

2002 ◽  
Author(s):  
A. R. Wadia ◽  
P. N. Szucs ◽  
D. W. Crall ◽  
D. C. Rabe
Keyword(s):  
Pressure Ratio ◽  
Flow Distortion ◽  
Two Stage ◽  
Good Efficiency ◽  
Guide Vanes ◽  
Stall Margin ◽  
High Pressure Ratio ◽  
Inlet Distortion ◽  
Inlet Guide Vanes ◽  
Current Production

Previous experimental and analytical studies conducted to compare the performance of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep with respect to aerodynamic performance and stability to multistage configurations. The experimental investigation compares, on a back-to-back test basis, two builds of an advanced good efficiency, high pressure ratio, two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained an already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs). The presence of the inlet guide vanes had a profound impact in lowering the two stage fan’s sensitivity with inlet distortion.

scholarly journals Flow Measurements Behind the Inlet Guide Vane of a Centrifugal Compressor

1998 ◽  
Author(s):  
I. Kassens ◽  
M. Rautenberg
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Guide Vane ◽  
Incidence Angle ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Flow Angle ◽  
Partial Load ◽  
Measurement Location

In a centrifugal compressor adjustable inlet guide vanes (IGV) in front of the impeller are used to regulate the pressure ratio and the mass flow. The stationary measurement of the velocity profile in front of the impeller with different angles of the IGV displays shock losses at the inlet edge of blade of the impeller. In the partial-load region (e.g. partial-load efficiency) the radial distribution of the flow influences considerably the performance of the impeller. The tested compressor consists of an adjustable IGV with straight vanes, a shrouded impeller and a vaneless, parallel diffuser. In the first measurement location, behind the IGV, total pressure, static pressure and flow angle were measured with a 5-hole cylinder probe. In the second measurement location, in front of the impeller, the measurement of the total pressure was carried out with a Kiel probe and the flow angle with a Cobra probe accordingly the static wall pressure was measured. Taking into consideration the fundamental thermodynamical equations it was possible to determine the velocity profiles because of the measured distributions of the flow angle in these two measurement locations. For different angles of the IGV and with various mass flows the distributions of the deflection defect behind the IGV are described. Starting with the measured distributions of the flow in front of the impeller the flow angles at the impeller inlet are calculated and the distributions of the incidence angle at the impeller inlet are figured out.

Variable Inlet Guide Vane Effect on Centrifugal Compressor Performance in Wet Gas Flow

2016 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Guide Vanes ◽  
Wet Gas ◽  
Compressor Performance

The introduction of variable inlet guide vanes (VIGVs) upfront of a compressor stage affects performance and permits tuning for off-design conditions. This is of great interest for emerging technology related to subsea compression. Unprocessed gas from the wellhead will contain liquid condensate, which affects the operational condition of the compressor. To investigate the effect of guide vanes on volume flow and pressure ratio in a wet gas compressor, VIGVs are implemented upfront of a centrifugal compressor stage to control the inlet flow direction. The guide vane geometry and test rig setup have previous been presented. This paper documents how changing the VIGV setting affects compressor performance under dry and wet operating conditions. The reduced performance effect and operating range at increased liquid content are of specific interest. Also documented is the change in the VIGV effect relative to the setting angle.

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